1.5% is equal to 0.015. Percents are always equal to their decimal counterparts; basically, the number over 100. Dividing 1.5 by 100 will yield us 0.015.
0.015 is going to be equal to 15/1000, or 3/200. Since we did 1.5/100, we need to multiply both sides of the fraction by 10 so there are no decimal points. Therefore, this is 15/1000. If we divide both sides of this fraction by 5, then we get 3/200, which is the most simplified form.
Divide the volume of the tank (10,000 gallons) by the filling rate of 250 gallons/minute and you will Hours = hr x min x 3785 ml x 55 gal = 208175 = 115.6 hrs.